The present invention relates to an apparatus for simultaneously disposing tubular labels on a plurality of bottles or containers and, more particularly, to an apparatus for disposing tubular or endless sleeve labels of the type which are supplied from a roll.
Sleeves or tubular labels having an endless shape have shown themselves to be particularly attractive for use as labels for bottles or containers. Such sleeves or tubular labels are most typically pre-printed plastic labels formed from thin flexible plastic film and these printed labels, commonly referred to as sleeve labels or tubular labels, have found wide use as labels for blow-molded plastic containers such as, for example, multi-liter soft drink bottles, other beverage bottles, and detergent chemical containers.
Tubular labels have proved to be cost effective as compared with other labeling techniques such as, for example, silk screen labeling techniques or adhesive label techniques, and one reason for this result has been the development of apparatus for automatically disposing such tubular labels on bottles or other containers, which minimize some of the labor-intensive steps typically involved in other label applying techniques. U.S. Pat. No. 4,944,825 discloses an apparatus for applying tubular labels to product containers, which includes a labeling assembly, a drive system for actuating the labeling assembly, and an assembly for advancing product containers to a label applying position. The labeling assembly is operable to repetitively separate individual tubular labels from a web comprised of tubular labels separably connected to one another. The labeling assembly is driven through a label applying stroke in which the assembly effects separation of the next available tubular label from the supply web of labels, draws the tubular label over a guide horn which opens the tubular label, and then draws the opened tubular label onto the product container. Before commencing its return stroke, the labeling assembly releases the tubular label which label contracts under its inherent bias and assumes a generally fixed mounted position on the product container.
As each product container is provided with a tubular label, the product container can then be discharged from the label applying position and the next product container awaiting labeling can be subsequently advanced into the label applying position. If a product container, especially one which is filled, is fed to the label applying position at too fast a rate, instability of the product container may occur, leading to movement of the product container to an extent that it may not be properly positioned for receiving its tubular label. The feeding and discharge of product containers into and out of the label applying position thus represents one step of the label applying process whose time requirements can only be reduced to a predetermined minimum level, regardless of the operating speed of the labeling assembly in performing other steps such as separating, opening, and inserting a tubular label on the product container.
Moreover, the driving movement of the labeling assembly through its label applying stroke and in the opposite direction along its return stroke cannot exceed a predetermined rate for the reason that incomplete opening and/or undesired plastic deformation of the tubular label may occur. Specifically, since the driving movement of the labeling assembly in its label applying stroke effects separation of the engaged tubular label along the separable connectors (e.g., perforations) between the engaged tubular label and the next following tubular label on the supply web, the rate of movement of the labeling assembly during the separation phase must be accomplished at a controlled rate so that plastic deformation of the tubular label (such as, for example, permanent axial elongation) does not occur due to a lag in the separation of the labels relative to the downward movement of the engaged tubular label. If the labeling assembly pulls the engaged tubular label at too fast a rate while the next succeeding tubular label is clamped during the perforation separating phase, one or both of the labels may stretch (e.g., axial elongation) beyond an elastic limit, thereby resulting in tearing or permanent plastic deformation of the tubular label.
Efforts to increase the efficiency of the tubular label applying operation have led to the development of one arrangement in which several tubular label applying apparatus are arranged together, with all of the apparatus receiving containers from a common feed device such as, for example, a linear conveyor. However, difficulties arise in reliably pre-positioning each group of product containers in the respective feed position at which they are fed in groupwise manner to the group of automatic tubular label applying apparatuses.
U.S. Pat. No. 4,694,633 to Fujio et al discloses a film wrapping machine for wrapping film around articles. Although the films do not have an endless shape such as a tubular label, the film wrapping machine disclosed in the Fujio et al patent is operable to apply film to a plurality of articles during movement of the articles between a feed location and the discharge location. The film wrapping machine includes a rotary turntable assembly supporting the articles at uniform spacings circumferentially about the rotary turntable assembly. A film supply unit supplies film to a film retaining member associated with each article during passage of the article past the film supply unit. The film retaining member associated with each article then applies the film in encircling relation about the article as the article continues to be advanced by the rotation of the rotary turntable assembly. However, due their endless shape, tubular labels must be moved axially over an article or container to apply the tubular label thereto and the Fujio et al film wrapping machine does not discloses a structure for applying a label of endless shape.
Accordingly, efforts to increase the speed at which automatic tubular label applying apparatus operate have been tempered by the reality that the rate at which product containers can be fed to, and discharged from, the label applying apparatus, and the rate at which tubular labels can be reliably separated from a supply web, inherently limit any significant increases in the production rate of the label applying apparatus.